Rescue efforts for missing miners were temporarily halted due to flooding Monday afternoon, one day after a coal mine flooding tragedy left 12 miners missing at Chaohua town of Xinmi city, central China's Henan province.

The fate of the missing miners remains unknown, said a spokesman for Zhengzhou Coal Industrial Corp., which owns the coal mine.

Twelve miners were reported missing in the accident that occurred around 4:00 p.m. Sunday when the corporation's Chaohua colliery was suddenly flooded.

Rescue efforts are now in a "crucial and difficult" period as six rescue teams are rushing against time to bring fresh air into the coal shaft, pumping out water and clean the mud, the spokesman said.

Preliminary investigation showed the tunneling of Chaohua colliery accorded with technical standards and unlicensed mining by other private pits above the working platform might be the cause for the flooding, the spokesman said.

With an annual production capacity of 2.4 million tons, the colliery is operated by the state-owned Zhengzhou Coal Industrial Corporation.

Source: Xinhua